1. Field of the Invention
This invention relates to a post-injection needle sheath and more particularly to a hypodermic syringe having a sheath.
2. Description of the Prior Art
Needle protectors are well known and have been in use for many years with the needles used with hypodermic syringes. Conventionally, needles are made with hubs and sockets adapted to be attached to the reduced end of a syringe. A molded plastic cap is conventionally removeably secured to the hub of the needle. After mounting the needle on the syringe, the cap is removed to expose the needle for use.
Accidental needle stick injuries are extremely common in health care workers, such as nurses, physicians, laboratory workers and housekeeping personnel. Needle stick exposures can result in transmission of hepatitis B, non A non B hepatitis, and, potentially, the acquired immune deficiency syndrome--AIDS, or other transmissible diseases. The health hazards associated with needle stick injuries are of greater risk for health care workers in the 1980's than ever before.
Accidental needle sticks often occur when a blood drawer attempts to recap a needle after use or leaves a contaminated needle exposed on work surfaces where the blood drawer or other workers accidentally impale themselves.
A modification of the current vacuum tube phlebotomy system is urgently needed to provide a protective barrier between health care workers and exposed, contaminated needles.
It is well known that used hypodermic needles are extremely susceptible to transmitting diseases. Hepatitis and other highly contagious diseases can be transmitted by successive use of the same needle by different individuals. In a hospital environment, however, precautions are taken to avoid use of contaminated needles by their expeditious disposal. Problems exist, however, in storing the needle for disposal and commonly the protective cap associated with the needle receives the used needle for discarding. However, it is apparent that the bore of the needle cap is dimensioned not much larger than the diameter of the needle and its needle base which removeably attaches to a syringe. Misalignment of the needle with respect to the cap when trying to reinsert the needle therein can cause the hand which holds the cap to be punctured, thereby increasing the likelihood of transmission of a contagious disease.
U.S. Pat. No. 2,847,995 and U.S. Pat. No. 3,134,380 are representative of shields used with hypodermic needles in which the shield or protector is adapted to be accordionized for use and then expanded to cover the tip of the needle. This type of needle-tip protector is contemplated to be mounted on the syringe or at least the needle hub and remain in a mounted condition during use. With the rapid increase in the AIDS-infected and human carriers, there has been a concentration of providing needle protection. U.S. Pat. No. 4,592,744 provides a specially constructed hub and a self-sheathing assembly. Deivces similar to this are known to the art and are utilized to provide a protecting extending flange secured to or as a portion of the tubular cap which is to be reinstalled to cover the needle. Shielded protectors which anticipate flanged extensions are numerous and have recently been promoted and/or offered as a protector of the attendant.
Also known are needle-tip protectors which anticipate attendant manipulation. Representative of these manipulable devices are U.S. Pat. Nos. 2,876,770; 2,925,083 and 3,306,290.
In the above-noted patents and as far as is known, there is a protector that is mounted on the needle and is in a stored and compressed condition and at the initial stage of use provides an exposed needle and, after withdrawal from the patient, provides a needle-tip protector to prevent unwanted and accidental pricking of the attendant by this needle tip. These patents showing needle protectors with spring means and manipulable actuation are expensive and contemplate rigid shield members. The present invention is adapted for use with the disposable syringes now used and with the sharp needle tip being protected substantially immediately, when withdrawal from the patient is made.